Internal expansion engine



3 Sheets-Sheet l /n Ven for* C. A l ramp/er- C. A. CRUMPLER INTERNAL EXPANSION ENGINE Filed July e, 1.939A

2\ [1HE Hu A Aug. 5, 1941 C. A. CRUMPLER INTERNAL EXPANSION ENGINE Aug. 5, 1941 3 Sheets-Sheet 2 Filed July 6, 1939 Aug 5, 1941- c. A. CRUMPLER INTERNAL EXPANSION ENGINE Filed July 6, 1959 3 Sheets-Sheet 3 m/.en for 61A. Crump/ef:

Patented Aug. 5, 1941 UNITED STATES PMN 1 Claim.

My invention relates to improvements in interna] expansion engines and the principal object of my invention is to provide a device of the character herewithin described which will enable such engines to operate on a double acting' principle by providing a fuel combustion chamber on both sides of the piston heads therein incorporated.

A further object of my invention is to provide a device of the character herewithin described in which a substantially greater operating enioiency is attained by reducing the number f` working parts to a minimum.

A further object of my invention is to provide a device of the character herewithin described, the output of which is nearly double the horsepower rating normally obtainable from a conven-l tional engine of the equivalent weight and. piston displacement. Y

A further object of my invention is to provide a device of the character herewithin described in which a smoother engine operation is produced by distributing the power impulses more evenly per crankshaft revolution than has been possible with a conventional engine having an equal number of single-acting cylinders.

A further object of Ymy invention is toprovide a device of the character herewithin described, in which the intake and the exhaust strokes of the pistons can be completely eliminated by a forcible admission and expulsion of the fuel charge, such action occurring simultaneously in each cylinder at the end of the piston travel before the compression stroke,

A further object of my invention is to provide a device of the. character herewithin described, which for the reasons of attaining exceptional simplicity and the absence of unnecessary Working parts, is capableof operating on a two-strokev Diesel principle. Its design, however, may be read-ily adopted in the construction of a four cycle engine, a two cycle engine, av flour" cycle Diesel, or any other convenient combination thereof- I 4 Y With the above more important objects in View and such other minor objects as may appear as the specification proceeds, my invention. consists essentially in the arrangement and construction of parts all as hereinafter more particularly described, reference being hadto the accompanying` drawings, in which:

Figure l is a sectionalA front elevation of my invention showing the same embodied' inV a three cylinder radial', two-cycle, Diesel type engine.

Figure 2 shows a side elevation in section, taken along the line 2 2 in Figure 1.

Figure 3 is a sectional front elevation of a cylinder, piston and sleeve assembly, illustrating the valve ports in an open position when the pist0nV is at the top dead center of crankshaft rotation.

Figure 4 is a perspective illustration of the cylindenpiston and sleeve assembly, showing the component parts in an extended view.

Figure 5 is a fragmentary front elevation of my invention modied for operation as a twocycle gasoline engine.

In the drawings like characters of reference indicate corresponding parts in the different figures.

My invention may briey be said to consist of a plurality of cylindersA arranged in a suitable relationship upon a orankcase B, and each containing a reciprocating piston C. The latter, in addition to being interposed within one of the said cylinders A is also slidable over a capped sleeve D by which arrangement two separate fuel combustion chambers are formed; namely, the anterior combustion chamber E and the interior combustion chamber F, the said chambers being located superjacently and subja-cently to the head of the piston C respectively. An alternate Vexplosion of a fuel mixture oc curring at predetermined intervals in the combustion chambers E and F drives the aforementioned pistons C from one end of their travel to the other and vice versa, which movement is transmitted by means of the conventional connecting rods G to a single throw crankshaft H.

In` the accompanyingV drawings the Figures 1 to l illustrate the principle as applied to a two cycle Diesel engine, a supercharger I and a fue] injector J are driven by the crankshaft H, the former supplying air under pressure to scavenge the products of combustion after the power stroke of the piston, and the latter injecting liquid fuel into a charge of compressed air before the commencement of the said stroke,

It will be observed, however, that by substituting a suitably actuated spark plug K in place of the injector J, as indicated in Figure 5 and employing a means of premixing the explosive fuel charge, the device will operate as a two cycle gasoline engine. Furthermore, a four cycle operation can be obtained by using a convenient arrangement of mechanically operated valves.

Referring now to my invention in detail, a reciprocating piston l is slidably positioned'within the bore of a cylinder 2 to form an anterior combustion chamber 3. A plurality of piston rings 4 are stationed in suitable ring grooves, provided in accordance with standard practice, in the piston skirt subjacent to the head I.

A circumferential flange 6 formed integrally with and projecting outwardly from the lower perimeter of the piston skirt 5 forms a reinforcement for a pair of diametrically opposed apertures "I, 1', in which the ends of a wrist pin 8 are secured. The reciprocating movement of the latter and of the associated piston I is transmitted in the conventional manner by means of the connecting rod S to a single-throw crankshaft I Ei journalled in suitable bearings II of the -crankcase I2.

The aforementioned cylinder 2 is secured to the crankcase I2 by means of a plurality of attaching bolts I3 passing through apertures I4 in a mounting flange I5 provided for such purpose on the lower extremity of the cylinder 2.

A capped sleeve I3 is positioned concentrically within the cylinder 2 as will be apparent from the illustrations and has its outer circumferential wall in compression contact with the inner wall of the piston skirt 5 to form an interior combustion chamber I6. A circular shoulder I'I formed on the base of the sleeve I6 engages an annular recess I8 provided in the lower wall of the cylinder mounting ange I5, thereby retain ing the said sleeve I5 in a stationary position in the lower end of the cylinder 2.

A portion I9 of the inner wall of the cylinder 2 within the reciprocating limits of the piston I, is of an increased diameter in order to facilitate the vertical movement of the projecting flange 5.

A pair of longitudinal, diametrically opposed slots 2E), 263', are formed in the cylindrical wall of the sleeve It wherein the aforementioned wrist pin 8 extending therethrough into the apertures 1, 1', may freely reciprocate.

A plurality of piston rings 2I stationed in suitable ring grooves provided in accordance with standard practice, are located in the lateral wall of the sleeve I 6 and maintain compression contact against the interior wall of the piston skirt 5.

Since the engine shown in Figures 1 to 4 is of a two-cycle Diesel type, two diametrically opposed valve ports, namely the intake valve port 22 and the exhaust valve port 23, are provided in the lateral wall of the cylinder 2, immediately above the level of the head of the piston I when the latter is in the lower dead center position.

A pair of similar diametrically opposed apertures 24 and 25 are provided in the piston skirt 5, in such position that when the piston I reaches the upper extremity of its travel, the apertures 22, 25, coincide with the aforementioned valve ports 22, 23 respectively. The action of the various valve apertures is effected by any conventional mechanism, their opening and closing being governed by the reciprocating movement of the piston I.

Referring now to Figure 2, a supercharger 25, driven through the medium of step-up gearing 2'I from the crankshaft IU is capable of delivering air under pressure through a connecting tube 28 to the inlet valve port 22 of the cylinder 2. A similar connection is made by means of the tubes 28', 28, to the remaining two cylinders of the engine. A short length of tubing 2Q connects the exhaust Valve ports 23 of all cylinders directly with the outside atmosphere.

The fuel injecting equipment comprises a suitably mounted fuel injector 3B driven by the crankshaft I U. Six separate injector outlet tubes 3l, 3I; 32, 32; 33, 33 are provided, the outlets 3I, 3l leading to their nozzles located in the stationary end walls of the anterior and interior combustion chambers 3 and I6 respectively. The outlet tubes 32, 32'; 33, 33 of course, inject the fuel into the anterior and interior combustion chambers of the two remaining cylinders of the engine.

The aforementioned injector nozzles are of the conventional design, and their point of entry into the interior combustion chamber I may be relocated from the cap of the sleeve I6 to a position in the circumferential wall of the cylinder 2. In such construction, an aperture should be formed in the piston skirt 5 in such positon as to uncover the injector nozzle when the piston I is at the upper extremity of its travel and facilitate the injection of fuel into the interior combustion chamber I 6'. The above mentioned arrangement will dispense with the necessity of introducing the injector connecting lines SI', 32 and 33 into the crankcase I2.

I do not claim the supercharger 26 and the fuel injector 29 together with the associated nozzles as a constituent part of this invention, and hence do not present a more detailed description thereof.

Having thus described the construction of my invention, I shall now proceed to describe its method of operation.

Considering the device to be in the position shown in the accompanying Figure 2, with the piston I passing the lower dead center of crankshaft rotation; it will be observed that the charge of air forced by the supercharger 25 through the valve port 22 will scavenge the products of the previous explosion from the combustion chamber 3 through the exhaust port 23.

As the piston I ascends, the valve ports 22, 23 will eventually be closed off and the charge of air remaining within the chamber 3 after the scavenging action will become compressed as the piston reaches the top of its stroke.

Simultaneously, the apertures 24, 25 in the piston skirt 5 will align with the valve ports 22 and 23 respectively, thereby permitting a scavenging action to take place within the int-erior combustion chamber I6.

As the piston I passes the top center of crankshaft rotation, a predetermined quantity of liquid fuel injected by the injector 29 through the connecting tube 3| into the anterior combustion chamber 3 will become ignited by the heat of compression of therein enclosed gases.

As the explosion occurs, the piston I will be forced downward, commencing its power of working stroke, simultaneously closing off the valve ports 22, 23 and compressing the air contained in the interior combustion chamber I6'.

At the lower extremity of piston travel, the valve ports 22, 23 will again open into the anterior combustion chamber 3 and permit a scavenging action of the exploded gases to be effected as already described.

Finally, the injection of fuel into the interior combustion chamber I6 through the connecting tube 3| will cause an explosion to occur in the said chamber, thereby propelling the piston I upwardly and completing the cycle of operations.

By placing the inlet valve port 22 at a somewhat higher location in the wall of the cylinder 2 in respect to the exhaust valve port 23, a longer duration of its opened interval will be produced.

By means of this construction a more complete scavenging of the products of combustion will be attained since a comparatively greater volume of fresh air will be admitted from .the supercharger.

It will be observed that an engine employing the aforesaid constructional design is doubleacting. An explosion of the fuel mixture occurring alternately on both sides of the reciprocating piston head counterbalances the compression stroke taking place simultaneously in the opposite combustion chamber, and thus produces a more regular rotation of the crankshaft.

Furthermore, by operating the engine on a twocycle principle, and forcibly scavenging the products of combustion by means of the supercharger, the intake and the exhaust strokes of the pistons are completely eliminated.

Referring now to Figure wherein a modified constructional design of my invention is shown, enabling the device to operate as a two-cycle gasoline engine, an explosive mixture of vaporised fuel and air previously combined in correct proportions in a suitable carburetor (not herein illustrated) is forced by the supercharger 26 into the combustion chambers 3 and i6' and ignited therein according to conventional practice by means of the spark plugs 34 and 35 respectively.

The latter are conveniently mountedwith their electrodes exposed within the aforementioned combustion chambers 3 and I6' and actuated at predetermined intervals by means of a suitable spark producing apparatus o-f a conventional design.

Finally, a four cycle gasoline principle may be incorporated in the engine design by employing in combination with the spark plug method of ignition above referred to any conventional cam-actuated valve lifting mechanism, driven directly by the crankshaft l0.

Since various modifications can be made in the above invention, and many apparently widely different embodiments of same, made within the scope of the claims Without departing from the spirit and scope thereof, it is intended that all matter contained in the accompanying specication shall be interpreted as illustrative only and not in a limiting sense and I desire only such limitations placed thereon as are specifically expressed in the accompanying claim.

What I claim as my invention is:

An internal expansion engine comprising the combination with a crankcase, 'crank shaft and connecting rod of a cylinder block having upper and lower tandem bores of different diameter, the lower bore being greater than the upper bore, a piston provided with a thickened outwardly projecting perimetric flange, said piston being slidable within said upper bore, the perimetric flange thereof moving within said lower bore but spaced from the wall thereof, a stationary cylindrical sleeve and cap, said sleeve being of less diameter than said upper bore and being provided with an annular flange and being positioned concentrically and predominantly between the upper and lower horizontally limiting planes of said lower bore, said flange being clamped between the annular contacting surface of said cylinder and said crankcase to secure said sleeve against longitudinal movement, said sleeve being also provided with a pair of diametrically opposed and longitudinally extending slots, the inner surface of the skirt of said piston being in working contact with the outer surface of said sleeve, anterior and interior compressed chambers being thereby formed, said anterior chamy ber by the head of said cylinder, said upper bore and the head of said piston, said inner chamber by said piston skirt, piston head and the cap of said sleeve, a wrist pin connecting said piston to said connecting rod, said wrist pin extending through said slots and terminating in diametric apertures formed in said perimetric flange, an inlet and an exhaust port upon said cylinder block to admit fuel into and discharge the products of combustion from said anterior compression chamber and an inlet port and an exhaust port communicating with said interior compression chamber to admit fuel thereinto and to discharge the products of combusion therefrom upon the movement of said piston.

CYRIL A. CRUMPLER. 

